Vertical SnSe nanorod arrays: from controlled synthesis and growth mechanism to thermistor and photoresistor

We demonstrate that high-quality vertically aligned SnSe nanorod (NR) arrays have been synthesized via a facile chemical vapor deposition method on SiO₂ substrates using Bi powder as catalysts. Both SEM and TEM measurements reveal that this kind of SnSe NR consists of a one-dimensional core and dense two-dimensional branches. Thermistors and photoresistors have been fabricated in situ by directly depositing silver paint on the growth substrates. The thermistor shows the great merits of a broad temperature range (77-390 K), linear input-output characteristic, suitable thermal index and high sensitivity. The photoresistor device exhibits relatively fast response time, linear input-output, high reversibility and stability. In addition, both of the devices have the advantages of low cost, environment-friendliness and easy fabrication. The high performance of SnSe thermistors and photodetectors will make SnSe material promising in industrial multi-function nanodevices.